Improvement in plungers for drawing tubular articles



J. s. PALMER. Plunger f0-r Dra, Win'g Tubular Articles.

No. 211.342. 'Pat'e'nted Jan. 14,1379.

Unrrnn ra'rns JOHN s. PALMER, or rnov nnivcn, nnonn ISLAND.

IMPROVEMENT IN PLUNGERS FO'R DRAWING TUBULAR ARTICLES.

Specification forming part ofLetters Patent No. 211,342, dated January14, 1879; application filed November 23, 1878.

CASE 'A.

To all whom it may concern:

Be it known "that I, JOHN S. PALMER, Of Providence, in the county ofProvidence and State of Rhode Island, have invented certain new anduseful Improvements in Tools Used for Drawing Metallic Shells from aDisk or Sheet of Metal; and I do hereby declare that the following is afull, clear, and exact description of the invention, which willenable'others skilled in the art to which it appertains to make and usethe same, reference being had to the accompanying drawings, and toletters of reference marked thereon, which form a part of thisspecification.

My invention relates to tools used for drawing metallic shells from adisk or sheet of metal, and usually known as drawingpunches, though theydo not punch a hole; and it consists in the special form andconstruction of the forward or operative end of such tools.

Tools of this class are usually made fiatended, and with the sharp edgeor angle of such end slightly taken 0% or beveled, and each successiveone of the series of tools is similarly made, but of smaller diameter;and whenever it is necessary that the finished article thus drawn intothe form of a tube closed at one end shall have a conical shape at suchend-as, for instance, in a oartridge-case-this conical part is formed atthe last drawing; but in the manufacture of finger-rings or otherarticles where plated metal is to be treated, usually called in thejewelry manufacture stock-plate-that is, a duplex or compound sheet orpiece of metal composed of a plate of base metal overlaid or plated witha more precious metal, such as an alloy of gold-the two metals havedifferent degrees of hardness, malleability, and ductility, the goldalloy being usually the harder one, and less malleable and ductile inits character; and there is therefore a liability of the alloy. toseparate from the baser metal when subjected to so severe a strain as isnecessarilyproduced by the square-ended drawing tool, so that the entireend or bottom that is presented at the first drawing action cannot beutilized because the alloy or more precious metal will crack or peel upfrom the soldering at that point or portion where the angle or cornerwas first turned up,

, so that only that portion which is turned up at the first drawing willbe perfect;

If a mere conical point upon the tool be used,

and such point be finished smoothly, as is required for the other partsof the tool, it will,

by reason of such smoothness, meet with but little resistance,especially in connection with the oil which is necessarily used topermit the withdrawal of the tubular metal from the forming tool, andthe effect is that the extreme point of the metal or shell undertreatment will be reduced to an undue and dispropor tioned thinness, andwill not be able to endure .the strains of the subsequent drawings, and

sharp advancing edges. or ridges at such an angle as to take hold of andfasten into the base metal of the shell under treatment whileit is beingformed or fashioned around the tool. This enables the enlargedbearing-surface afforded by the conical end, as contrasted with a fiatend of atool, to sustain its full and equal proportion of the drawingstrain upon the cylindrical body of the shell, and no breaking up of theplated metal from its soldering, and that all the metal down to thesmallest size needed to be drawn will be utilized and its integritypreserved throughout all of the successive drawings.

Instead of annular grooves with sharp edges, the conical point may haveprojecting points or spurs, as shown at b and b in Figs. 2 and 3,adapted to take hold of and fasten into the baser metal of the shell, asabove mentioned; or it mayhave both the sharp ridges and the points, andthese as well as the grooves and sharp edges may be located or disposed011 the cone in any preferred manner so long as they are adapted to takea hold or purchase upon the base metal to effect the end sought, asheretofore explained.

In the drawings, 0 represents a die for drawing, and d a blank of platedmetal to be drawn by means of the die and the tool a; e, a shell made bythe first drawing; f, the same reduced by four successive drawings andready for rolling; g, a wire core to be inserted in the shell, ifdesired, or left out altogether, during the subsequent processes ofrolling.

When a core is used, the gold or alloy of the shell should be twice asthick as is required when such core or wire is not used, in order toproduce in either case an article of the same weight of precious metal,and for the reason that when the shells are afterward reduced by rollingthey will admit of being rolled out to about twice the length with thecore inside that they can be without such core, such increase of lengthnecessarily reducing the thickness of the gold proportionately unlesspreviously made thick enough to compensate for such reduction. Theweight of the wire core should be about the same as the weight of theshell; but it may be either larger or smaller, as desired.

The subsequent process of rolling, for the purpose of preparing andshaping or fashioning these drawn shells, to adapt them for being madeinto various articles-such as fin gerrings, parts of musical or surgicalinstruments, and other articles-need not here be described; and myimprovements in rolling will form the subject-matter of another andindependent application for a patent. I

I claim A tool for drawing metals having a coni cal point provided withgrooves 01'' their described equivalents, presenting sharp points oredges to fasten into or take hold otfltho base metal of the shell orstock, substantially as described.

JOHN S. PALMER.

Witnesses EBEN W. WATERHOUSE, GEo. G. TOWNSEND.

